Stories tagged pollination

It's Friday, so it's time for a new Science Friday video. Science Friday
Science FridayCourtesy Science Friday
"Of the orchid genus catasetum, Charles Darwin wrote: "I never was more interested in any subject in all my life than in this of Orchids." The male flowers in this genus evolved an unusual pollination program. They propel a package of pollen onto the backs of visiting bees. The bees endure the blow (which would be like a 150-pound person getting hit with a few bowling balls) in exchange for orchid aromas that the bees use to attract mates.

Mmmm, mmmm good: Is there anything better than a summer day and a slice of watermelon? I'll take my watermelon with seeds or without; I'm not picky.
Mmmm, mmmm good: Is there anything better than a summer day and a slice of watermelon? I'll take my watermelon with seeds or without; I'm not picky.Courtesy foreversouls
Remember the good old days of summer when you could chomp on a slice of watermelon and spit out the seeds? Those Tom Sawyer moments are getting far and few between with the growing popularity of seedless watermelon. In fact, when you go to the store, it’s hard to find a watermelon these days with the conventional hard, black seeds.

How can a watermelon grow without seeds?

Seedless watermelons have been around for more than 50 years. And while they’re called “seedless,” they actually do have small white seeds in them. What they don’t have are the large, hard black seeds that no one wants to swallow. So how do they grow? It all boils down to the chromosome level. Chromosomes are the genetic building blocks in all living things that give them their physical traits.

Watermelon breeders have discovered that if you cross breed a watermelon with two sets of chromosomes with one that has four sets of chromosomes, you end up with a melon with three sets of chromosomes. That’s called a triploid seed, and when planted, it produces a watermelon that produces small seeds that won’t reproduce. It’s the plant world equivalent of a crossing a horse and a donkey to get a non-reproducing mule. Here's a link to an NPR report about how seedless watermelons, and other seedless fruits, are developed.

While consumers have expressed their strong preference for seedless watermelons, that hasn’t put the seeded varieties out to pasture, so to speak. Seeded watermelons still play a crucial role in the production of seedless watermelons.

Along with the crossbreeding work that’s needed to create seedless watermelon seeds, seeded watermelons need to be planted among seedless watermelons for their fruit to develop properly. A field producing seedless melons will have around 25 percent of its plants being seeded melons to help in the pollination process. Bees cross pollinate between the two plants. Without that cross pollination, the inner fruit of the watermelon will not develop.

And no one would want that, now, would we?